Effects of gravity and surface tension on steady microbubble propagation in asymmetric bifurcating airways.
Effects of gravity and surface tension on steady microbubble propagation in asymmetric bifurcating airways.
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DOI：
10.1063/5.0012796
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发表时间：
2020-07-01
期刊：
影响因子：
--
通讯作者：
Xu Y
中科院分区：
文献类型：
--
作者：
Munir B;Xu Y
如今，机械通气是急性呼吸窘迫综合征患者生存的一种成熟、安全且必要的策略。然而，机械通气时气道分叉处微泡的传播使得已有的肺损伤更加严重。本文利用有限元和直接界面跟踪技术来模拟充满粘性流体的二维不对称分叉气道中的稳定微泡传播。忽略惯性效应，使用斯托克斯方程的数值解来研究由邦德 (Bo) 数和毛细管 (Ca) 数定义的重力和表面张力如何影响分叉子气道壁上的压力梯度、剪切应力和剪切应力梯度的大小。研究发现，Bo 的增加显着影响气泡形状和流体动力应力，其中 Bo ≥ 0.25 导致气泡高度和上子壁压力梯度显着增加。虽然对于 Bo 和 Ca 来说，上子气道壁的压力梯度大小总是大得多，但 Ca 对放大压力梯度大小有很大作用。总之，重力和表面张力对于分叉气道中微泡的稳定传播和流体动力应力起着关键作用。
Mechanical ventilation is nowadays a well-developed, safe, and necessary strategy for acute respiratory distress syndrome patients to survive. However, the propagation of microbubbles in airway bifurcations during mechanical ventilation makes the existing lung injury more severe. In this paper, finite element and direct interface tracking techniques were utilized to simulate steady microbubble propagation in a two-dimensional asymmetric bifurcating airway filled with a viscous fluid. Inertial effects were neglected, and the numerical solution of Stokes’s equations was used to investigate how gravity and surface tension defined by a Bond (Bo) number and capillary (Ca) number influence the magnitudes of pressure gradients, shear stresses, and shear stress gradients on the bifurcating daughter airway wall. It is found that increasing Bo significantly influenced both the bubble shape and hydrodynamic stresses, where Bo ≥ 0.25 results in a significant increase in bubble elevation and pressure gradient in the upper daughter wall. Although for both Bo and Ca, the magnitude of the pressure gradient is always much larger in the upper daughter airway wall, Ca has a great role in amplifying the magnitude of the pressure gradient. In conclusion, both gravity and surface tension play a key role in the steady microbubble propagation and hydrodynamic stresses in the bifurcating airways.
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DOI：
10.1016/j.ijheatfluidflow.2005.10.002
发表时间：
2005-12-01
影响因子：
2.6
作者：
Eshpuniyani, B;Fowlkes, JB;Bull, JL
通讯作者：
Bull, JL
DOI：
10.1051/m2an:2000110
发表时间：
2000-09-01
期刊：
ESAIM-MATHEMATICAL MODELLING AND NUMERICAL ANALYSIS-MODELISATION MATHEMATIQUE ET ANALYSE NUMERIQUE
影响因子：
--
作者：
Chizhonkov, EV;Olshanskii, MA
通讯作者：
Olshanskii, MA
影响因子：
3.3
作者：
Dailey, H. L.;Ricles, L. M.;Ghadiali, S. N.
通讯作者：
Ghadiali, S. N.
影响因子：
4.6
作者：
Dbouk, Talib;Drikakis, Dimitris
通讯作者：
Drikakis, Dimitris
影响因子：
4.1
作者：
HALPERN, D;GAVER, DP
通讯作者：
GAVER, DP